How Shipmunk builds an app

How Shipmunk builds an app, step by step

Every app goes through the same path. You describe it, the builder asks what it needs to know, and you approve a plan before anything is built. Then the checks are written, the app is built in a private container, and the checks run until they pass. Here is the AI app builder workflow from start to finish.

1. Pick the kind of app

   Home opens on "Build a phone app": a native React Native app made with Expo, which you open in Expo Go. Under "Other kinds of app" you can build an MVP, add a feature to an app you already have, or pick "Something else" for a tool, dashboard, pipeline or assistant. Read more about building phone apps with Shipmunk.

2. Write the brief

   Describe the app in a sentence or two. Type it, or press the microphone and say it. You can also attach up to 10 files, 20 MB together: Markdown, PDF or images (PNG, JPG, WEBP, GIF). The builder reads the text in each document and a short description of each image.

3. Answer a few focused questions

   The builder reads your brief and asks at most five questions, one at a time. Pick an answer or write your own, by typing or speaking. If you skip, each remaining question takes its default answer, or the part it asks about is simulated. A question that truly needs you stops the skip there.

4. Read and approve the plan

   The plan lists every part of the app and marks each one Real or Simulated. It shows the tools in your sandbox, what will be checked, the most the build can spend in credits and a typical cost. You can ask for up to three plan changes a day. Nothing is built until you press "Approve and build".

5. Checks are written first

   The plan includes the check files. For each part they cover the main flow, a refusal, the seeded data and the recorded state of each simulated tool. The builder reads the checks before it writes code, and it has to change the app to meet them. The check files are restored before every test run, so an edit to them is thrown away.

6. The build runs in a private container

   Each build runs in its own container, with a time limit. The timeline shows each step as it happens: planning, setting up a private workspace, writing the code, running the checks and packaging the result. See how Shipmunk keeps builds isolated.

7. Check, fix, check again

   After each round the checks run. For an app with screens, a browser check also opens its pages at desktop and phone widths. It fails on page errors, failed requests, sideways scrolling on a phone and serious accessibility problems. A reviewer model reads the results, screenshots and code, then sends the builder back to fix what failed. A build gets up to four fix rounds. If a later round breaks a check that an earlier round passed, the passing round is the one you get.

8. Try the preview

   A finished web app has a live preview you open in a new tab. A phone app opens in Expo Go: on your phone, tap "Open in Expo Go" or scan the QR code. On a computer, you can try it on a cloud Android phone streamed into the page. Previews run for a limited time and say when they end.

9. Ask for changes in a conversation

   Under "Change something", say what should be different, for example "Add a waitlist when a class is full". Each change builds a new iteration and keeps the rest of the app. You see the most it can spend before you send it, and your changes stay listed as a thread.

10. Share it or download the code

    When a build is ready you can share a short card that says how long the build took and how many checks passed, as copied text or a post on X or LinkedIn. You can also download the code as a zip, with a README that explains how to run, test, configure and deploy it.

What you get at the end

Each iteration has its own page. It is the record of what was built and how it was tested.

Parts that talk to outside tools such as Stripe, Slack or Gmail run against realistic stand-ins marked "Simulated". The Shipmunk Sandbox explains how those stand-ins work and how the checks use them.

What still needs you before launch

The Sandbox is the rehearsal. A passing build tells you the app does what the checks describe, against simulated tools and seeded data. It does not make the app ready for real customers on its own.

• Simulated parts stay simulated until you connect the real service. Press "Make it real" on a part, tell the builder what the real one uses, and it rebuilds only that part.
• Launching still requires live accounts, provider approval and production checks.
• Running the app for real is yours. The downloaded code comes with a README, so you or a developer can run, configure and deploy it.

Shipmunk helps you reach that stage with fewer unknowns.

What a build costs

Builds use credits, charged for the AI and compute a build uses. The plan shows the most a build can spend before you approve it, and each change shows its own limit before you send it. If you cancel an iteration, the builder stops after its current turn and what it spent so far is charged. Shipmunk is in closed beta. More answers are in the Shipmunk FAQ.